package org.aphelie.torg.ruler.internal.core.ischema;

/**
 * Objects that implement this interface hold data about attributes of schema
 * elements.
 */
public interface ISchemaAttribute extends ISchemaObject, IMetaAttribute {
    /**
     * This attribute can be omitted by the extension element.
     */
    public static final int OPTIONAL = 0;

    /**
     * This attribute must be defined in the extension element.
     */
    public static final int REQUIRED = 1;

    /**
     * This attribute can be omitted by the extension element, and if it is, its
     * value will be set to the value defined in the "value" field.
     */
    public static final int DEFAULT = 2;

    /**
     * Table of the 'use' clause choices.
     */
    public static final String[] USE_TABLE = {"optional", "required", "default"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ 

    public static final int BOOL_IND = 0;
    public static final int STR_IND = 1;
    public static final int JAVA_IND = 2;
    public static final int RES_IND = 3;
    public static final int ID_IND = 4;
    public static final String[] TYPES = {"boolean", //$NON-NLS-1$
            "string", //$NON-NLS-1$
            "java", //$NON-NLS-1$
            "resource", //$NON-NLS-1$
            "identifier" //$NON-NLS-1$
    };

    /**
     * Returns the type of this attribute. Attributes can only have simple
     * types.
     */
    public ISchemaSimpleType getType();

    /**
     * Returns the 'use' mode of this attribute (OPTIONAL, REQUIRED or DEFAULT).
     */
    public int getUse();

    /**
     * Returns the default value of this attribute when 'use' clause is DEFAULT.
     */
    public Object getValue();

}
